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I've seen it quite a few times. Someone answers their cell phone mid-flight - BOOM! Down goes the plane, steep descent, passengers screaming, masks drop from t
by hoodoof 10y ago
I've seen it quite a few times.
Someone answers their cell phone mid-flight - BOOM! Down goes the plane, steep descent, passengers screaming, masks drop from the ceiling, until that phone call ends and the plane straightens up.
Blanket ban on electronics is the only way to stop this happening.
One time I was flying and someone had forgotten to turn off their phone until the plane was in the air and it interfered with the navigation systems and we landed in London instead of Paris. Very ocnfuisng.
- Cyph0n 10y agoI'm not sure if you're joking or not... Regardless, the ban does not affect cell phones.
- rangibaby 10y agoJoking for sure. When I flew domestic in China people were using their phones the whole time.
- Cyph0n 10y agoI'm aware that using a phone on a plane does no harm, but I just wanted to make sure you didn't actually mean it.
- lb1lf 10y agoSure it does. To the cellphone networks. (Unless the aircraft carries its own picocell). The big problem with cellphones on planes is that they overwhelm the signalling networks on the ground - when the carrier tries to determine which cell is best suited to handle your call, it basically polls the neighbouring cells for the received signal strength from that particular phone. When you're on a plane, your phone is seen from an awful lot of cells. Also, some systems (GSM, for instance) relies on your velocity compared to the base station not being too large to allocate you a slot in the time-multiplexed channels. Depending on the geometry of the cell network, you may not be able to connect at all when on a plane - but your phone may create all sorts of grief for the network operator. Or, put another way - if there really was a non-zero probability that a working cellphone on a plane would cause trouble, the TSA would simply collect the phones during boarding and being caught with one would give you the full terrorist treatment. Given the abundance of cellphones and the sloppiness of people, I think it is probably safe to say that no commercial flight has taken off without at least one active cell-phone aboard for the past twenty years or so.
- TeMPOraL 10y agoI wonder, don't cellphone networks have ways to handle it? E.g. if they detect a phone that behaves as if travelling 13km up at 900km/h, couldn't they just tag it as "in flight" and ignore it for the next few minutes?
- lb1lf 10y agoI don't know, to be honest - I do suspect the problem is much smaller now that 3/4G is a thing, though - higher data rates means smaller cells means more directional antennas, and presumably carriers will not waste energy beaming skyward - so maybe airborne phones don't see as many cells as they used to (if any). It would be non-trivial to determine the phone's altitude, but you could make a pretty good inference from the number and location of cells reporting that they 'see' it - and the velocity should be a no-brainer to figure out with a reasonable degree of accuracy. Hm. Just a semi-educated guess. (I haven't looked at cellular systems since I was in university 15-20 years ago.) Methinks you are probably right.
- dboreham 10y agoExcept...the cell sites typically use antennas that have a high gain in the veritcal axis, meaning very low gain in the direction of high flying aircraft and a low probably that transmissions from phones inside a faraday cage at said high altitude will rise above its receiver noise threshold.
- mikeash 10y agoI'm skeptical that it really causes trouble for phone networks. In my experience flying small airplanes, getting a signal is easy below about 4,000ft, starts getting spotty up to 6,000ft, and is basically impossible above that. Which makes sense: antennas at the cell will be aimed sideways, not up, so the only cells you might be able to talk to would be really far away. And this is in a fiberglass airplane that's basically radio transparent. Now try it in an aluminum airplane at 30,000+ft. I doubt the cells can even hear your phone in the first place.
- lb1lf 10y ago
- necessity 10y agoThat's funny because in China it's forbidden to use it even on airplane mode.
- ptaipale 10y agoSometimes in China, the thing is not lack for things being forbidden, it's the lack of enforcement culture.
- hrrsn 10y agoI'm guessing you forgot the /s tag.
- GrinningFool 10y agoI'm thinking when he says he's seen it multiple times, the /s tag is implicit.
- sitepodmatt 10y agoLove it. I laughed more though at the comments to this - one person genuinely not sure if humor or not, and one guy, smart, that somehow managed to figure it out without a /s. Welcome to next generation of software engineers.
- Cyph0n 10y agoYou must be new to the internet. I hope you're aware that people sometimes spout nonsense they genuinely believe in. I know it's HN, but I like to keep my guard up ;) Let's say you saw a similar comment on HN describing why the Earth is flat. Would you have reacted the same way?
- dragonwriter 10y agoIt's plausible that someone could genuinely (if unjustifiably) believe that the Earth is flat. It is far less plausible that they could genuinely believe they have witnesses, first-hand, several instances of a passenger using a cellphone on a commercial flight and causing it to crash, plus instances of navigation and other failures caused by personal electronics.
- Cyph0n 10y agoYeah, I'm going to need some stats on that.
- TeMPOraL 10y agoSometimes a person can keep pretending they believe in the nonsense they write longer than you can believe they're only joking. Such is the Way of the Troll.
- alkonaut 10y ago> Very ocnfuisng. That's an RF induced race condition. Someone may be using radiowaves next to your keyboard. Now imagine that happening to the auto pilot system.